Answer: Option A - as the direct initiator of the cough reflex
Explanation:
The cough reflex has sensory and motor components. The cough receptors within the epithelium of the respiratory tract are usually sensitive to chemical stimuli as well as mechanical stimuli. Very slight or minute amount of foreign objects and other irritation causes initiate the cough reflex due to high sensitivity of the trachea and bronchi to very light touches.
Air in motion normally conveys some amount of dusts, foreign objects or matter that tends to settle in the trachea or bronchi. The human respiratory system is designed in such a way that these foreign matter or dust that settled in the bronchi or trachea will then stimulate the cough receptors, thereby producing a cough. This cough is extremely vital in getting rid of these dust particles or foreign matter from the tract before it approaches the lungs.
The nose is the organ that acts as part of the respiratory system. It is the human organ for smelling. It is through the nose that air enters into the human body. Our brain recognizes smell the instance air goes through some cells within the olfactory system. The task of cleaning the air and separation of foreign particles is carried out by the hairs in the human nose. When air flows down the respiratory tract via the nasal passages, the nose warms and humidifies it before it gets to our lungs.
Conclusively, it is clear that the human nose is responsible for warming and humidifying the air, acts as a passage way for air movement and cleanses the air. Therefore the only thing (from the options) that the nose is not directly responsible for is initiating the cough reflex.
